With the rapid development of the global industry, the life environment is gradually worsening, and especially the discharge of a large amount of wastewater containing heavy metals causes serious pollution for the environment. The heavy metals may be introduced into a human body through a food chain step by step and accumulate in the same continuously, and therefore have become serious threats to human health. The problem of how to efficiently achieve remediation of the water body containing heavy metals is currently a global concern.
Conventional methods for the purification of wastewater containing heavy metals mainly include chemical sedimentation, physical adsorption, biotreatment, ion exchange, membrane separation, micelle enhanced ultrafiltration, polymer complexed ultrafiltration, electrochemical method, etc. These conventional methods are disadvantageous in that they have a low selectivity for heavy metals and may cause secondary pollution, and therefore contrary to the removal and recovery of the heavy metals.
The concept for the treatment of industrial wastewater mainly focuses on the removal, recovery and reuse of the heavy metals. To achieve purification of a large amount of industrial wastewater such that discharge standards can be met and the heavy-metal ions can be separately recovered, an adsorbent is needed to be filled into a fixed bed. Although many small and medium enterprises facing a problem of serious heavy metal pollution have successively introduced adsorbent fixed-bed wastewater recycling devices, it is difficult for the prior art to remove heavy metals from the wastewater and separately recover highly pure heavy metals simultaneously due to that, in practice, the industrial wastewater contains a plurality of different kinds of metal ions and is complex in components.